An embodiment of the invention generally relates to methods and systems for testing a light sensor, and in particular to a test system that associates segments of sensed data sequence with respective, physical test areas based substantially on analysis of the sensed data and sensor data patterns and not based on timing information. Other embodiments are also described.
Modern portable electronic communications devices such as smart phones often include various sensors. Incorporation of sensors into portable electronic devices has facilitated the automation of a variety of tasks that traditionally require human input. For example, an ambient light sensor (ALS) integrated in a portable electronic device may detect available environmental light surrounding the device and report this light level to a screen adjustment unit. Based on this value, the screen adjustment unit may adjust the brightness of the portable electronic device's screen to allow a user to easily read the screen in variable lighting conditions without compromising battery life.
Although sensors integrated into portable electronic devices provide useful functions, their effectiveness is limited by their accuracy. In particular, a sensor which produces inaccurate readings likely will be ineffective and will cause the portable electronic device to be manipulated in an undesirable manner. For example, an ALS integrated into a portable electronic device which reports light levels at lower than actual values may cause the screen of the portable electronic device to be dimmed in a bright environment. This in turn will hinder a user's ability to read the dim screen in a relatively brighter surrounding environment.
In an effort to ensure the accuracy of sensors integrated within portable electronic devices, manufactures perform numerous tests of the sensors prior to releasing the devices to retailers. In a traditional method and system for testing a sensor integrated within a device under test (DUT), the DUT is placed on a conveyor belt and fed through a variety of areas or zones. Each zone or area presents a different testing scenario or environment by which the accuracy of the sensor within the DUT is tested. In each scenario, the sensor produces values corresponding to the given environment and these values are then stored. The stored values are then subsequently accessed and analyzed by dedicated test equipment to determine the accuracy of the sensor. Since various scenarios are being tested in succession, the times at which the DUT enters and exits each area or zone needs to be determined in order to ensure that the correct reference values are compared against the appropriate sensed data.
This timing information was obtained by painstakingly recording the times at which the DUT entered and exited each zone as the DUT traversed each zone. This system thus requires that detailed timing information be generated, recorded, and analyzed for each DUT.